Some of the conventional hand tools such as wrenches and sockets have a layer coated on the outer surface thereof for the aesthetic purposes and are disclosed in U.S. Pat. Nos. 6,082,227 and 7,028,588. The conventional ways to coat the layer include dying, Nickel electro-coating, Chromium electro-coating, Titanium electro-coating, Tin electro-coating, color electro-coating, painting, coloring and other known methods so as to improve the outer appearances of the tools and the size data can be seen from the coated layer.
The size of the tools is fixed so that the manufacturers often do not put the coated layer in consideration, especially that the coated layer does not affect the operation of the tools. However, the coated layer can be up to 0.5 mm which may affect the operation of ratchets. As shown in FIGS. 12 to 14, the ratchet 50 has a coated layer 60 coated thereon and the surfaces 51 of the ratchet teeth 500 are also coated with the coated layer 60 so that the height of the teeth 500 is increased and the gap 52 between the teeth 500 is reduced. The surface 61 of the coated layer 60 is not strong when the teeth 500 are operated so that the torque transmitted by the ratchet 50 is reduced. When the ratchet teeth 500 are engaged with a pawl, the depth that the teeth 500 are engaged with the pawl is reduced and the torque transmitted is reduced. If the ratchet is larger than 19 mm, the height from the bottom of the teeth to the tip of the teeth is 0.58 mm and the thickness of the coated layer 60 is 0.5 mm so that only a limited portion of the teeth is remained. The torque is reduced slightly. However, if the ratchet is a smaller one such as 8 mm ratchet, the height from the bottom of the teeth to the tip of the teeth is 0.28 mm and the thickness of the coated layer 60 is 0.5 mm so that there will be no teeth left and the engagement between teeth is failed, the lost of torque is significant. This is especially obvious for the ratchets of 8 mm to 15 mm.
The present invention intends to provide a ratchet with a coated layer which improves the outer appearance and provides more distinguishable feature, while the shape of the ratchet teeth is maintained.